<!-- 钩子函数 页面挂载 -->
<script src="./vue.js"></script>

<div id="app">
    <P>{{msg}}</P>
</div>

<script>
    var vue = new Vue({
        el: '#app',
        data: {
            msg: "我有回来了"
        },
        mounted(){
            console.log("页面挂载之后")
            console.log(this.$el.innerHTML)
        },
        beforeMount(){
            console.log("页面挂载之后")
            console.log(this.$el.innerHTML)
        }
    })
</script>